Chaney restated his support for the exchange Thursday before members of the Mississippi Economic Council, which was holding its Capital Day meeting in Jackson. In the front row of the audience was Gov. Phil Bryant, whose opposition led federal officials to question whether Mississippi’s proposal should go ahead.

Exchanges are online marketplaces where people can shop for insurance. Under the federal health law that President Barack Obama signed in 2010, every state is required to have an exchange so people can get coverage starting in January 2014, much of it federally subsidized. States that don’t create their own will have one run by Washington.

Chaney has led a process funded by federal grant money to design a state-run exchange. He submitted it to the federal government for approval. But Bryant, a fellow Republican, intervened with a letter to U.S. Health and Human Services Secretary Kathleen Sebelius saying the insurance commissioner lacks the legal authority to create an exchange on behalf of the state. Bryant said only he has that power.

Earlier this month, the Department of Health and Human Services said it had approved exchange proposals for Washington, D.C., and 17 states, four of which have Republican governors.

Chaney said he expects the federal decision to turn not on his authority, but on whether a state exchange will be able to adequately coordinate with Medicaid and other programs Bryant controls if the governor remains opposed.

Bryant and other Republican governors who oppose exchanges have said they fear that the exchange will give the federal government a back-door way to force the expansion of Medicaid, which is also envisioned to be part of the federal health care law.

“We just need to be very careful before we create a portal for Obamacare,” said Bryant, who also opposes Medicaid expansion.

Chaney, though, said the danger of the federal government diverting people from the exchange to Medicaid will be greater if the state doesn’t run the exchange.

“If the feds operate the exchange, they’re going to put them on Medicaid,” Chaney said.

He said the state would save money if it ran the exchange and could use federal subsidies for insurance buyers there to draw some people off Medicaid.

The Mississippi Health Advocacy Program reiterated its support Thursday for a state-based exchange.

“Right now too many middle-class families have nowhere to turn if they lose the coverage offered by their employer,” said Roy Mitchell, the program’s director. “A Mississippi-run insurance exchange will guarantee individuals a secure place to go to get quality, competitively priced health plans if they lose their job or want to start their own business.”